JP-2006-290024-A discloses a vehicle brake hydraulic pressure controller having functions for skid suppression control and traction control. There may also be a controller further having numerous functions, such as functions for brake assist control and brake force holding control during vehicle stop.
The above-mentioned various functions may be respectively carried out in different situations. For example, when the vehicle stops, operation noise generated during the control is conspicuous because there is no road noise, and the noise is requested to be low. However, generally speaking, when brake hydraulic pressure control is performed, proportional solenoid valves are driven at constant drive frequency, regardless of the situation of the vehicle. Hence, when brake control is performed during vehicle stop in the case that the drive frequency is low, unpleasant noise is likely to be transmitted to the ears of the driver and passengers.